A high voltage power management integrated circuit (PMIC) requires a unique layout and design techniques in order to transmit control signals from a low voltage regime to the high voltage domain and vice versa. This is especially acute when the high voltages are of the order of thousands of volts on the edge or beyond what silicon can sustain.
Signal transmission across high voltage isolation can be materialized by optical, inductive or capacitive or direct link via a high voltage device. At high voltages, where a direct device link may not be possible or desirable, the capacitive solution are usually simpler than the others but often used requires an off-chip high voltage cap that is expensive and bulky.